This invention relates generally to a vehicle axle beam, and specifically to a method of fabricating a vehicle axle beam with a varying wall thickness.
Conventional solid axle beams have been used for vehicle axles. The solid axle beam provides a rigid, durable structure capable of withstanding the bending and torsional loads typically encountered. The bending and torsional loads on an axle beam are not uniform. Some segments of the axle beam experience less loading then other segments and may not require the same structure. A solid axle beam is relatively heavy and adds considerable weight to a vehicle.
Conventional hollow axle beams reduce weight while still providing the structure to bear the bending and torsional loads encountered by a vehicle axle. Typically, a hollow axle beam is formed from a round or square tube section. Round or square tube sections are typically formed from a single sheet of material rolled or folded to abut along longitudinal segments. The seam formed by the abutted longitudinal segments is then welded. A square tubular section provides favorable bending loading performance. Bending loads are primarily carried across two sides of the square beam. The two loaded sides are required to be of a minimum thickness. Disadvantageously, non-loaded sides of the square tube are of the same minimum thickness required of the loaded sides.
Accordingly, it is desirable to design an axle and method of fabricating an axle having a wall thickness tailored to the expected load.